Bilology I TEST CH. 3
Terms
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- observed a thin slice of cork in 1665 and coined the term "cells"
- Robert Hooke
- discovered "animalcules" or tiny animals today known as single-cell organisms
- Anton van Leeuwenhoek
- scientists express measurements using...
- metric system
- SI units are based on what power?
- powers of 10
- light passes through one or more lenses to produce an enlarged image
- light microscope
- forms an image of a specimen using a beam of electrons
- electron microscope
- ability to make an image appear larger
- magnification
- measure of clarity of an image
- resolution
- electron microscopes cannot view what?
- living cells
- electron beams much shorter ___________ than that of visible light
- wavelength
- 2 kinds of electron microscopes: ____________ ____________
- transmission: electron beam directed on a thin slice of specimen that's been stained scanning: focused on a specimen coated with a very thin layer of metal
- the observations of the scientists Schleiden, Schawnn, and Virchow formed what?
- cell theory
- the cell theory consists of three things:
- 1. All living things are made of one or more cells. 2. Cells are the basic units of structure and function in organisms. 3. All cells arise from existing cells.
- ______ trillion cells in the human body
- 100
- ______ cells can exchange substance more rapidly than large cells because small objects have a higher surface-to-area-_______ ratio than larger objects
- small volume
- outer boundary
- call membrane
- interior of a cell
- cytoplasm
- microscopic fibers that support the cell(like bones)
- cytoskeleton
- cellular structures on which proteins are made
- ribosomes
- single cells organism that lacks a nucleus and other internal componets
- prokaryote
- cannot carry out many _______ functions
- specialized
- prokaryotes are informally called...
- bacteria
- enzymes and ribosomes are free to move around the cytoplasm because lack of...
- internal structures
- bacteria cells have a...
- cell wall
- these cells lack a ________, so they must rely on a strong cell wall for support
- cytoskeleton
- long, threadlike structures that protrude from the cell's surface and enables movement
- flagella
- an organism whose cells have a nucleus
- eukaryote
- an internal compartment that houses the cell's DNA
- nucleus
- structure that carries out specific activities in the cell
- organelle
- short hair-like structures protrude from the surface of some euk cells
- cilia
- instructions for making proteins
- DNA
- cytoskeleton is made up of ________ and _________
- microtubules microfilaments
- cell membranes form..
- a barrier
- cell membranes are caused mainly by the way _________ interact with water
- phospholipids
- lipid made of a phosphate group and 2 fatty acids
- phospholipids
- in a cell membrane, the phospholipids are arranged in a double layer called a...
- lipid bilayer
- attached to a carb on the cell's surface, help other cell's recognize their cell type
- marker proteins
- recognize and bind to specific substances such as signal molecules outside of the cell
- receptor proteins
- move stuff in and out of the cell
- transport proteins
- substances that are made in the nucleus, including ribosomal proteins and RNA, move into the _________ by passing through the ______________.
- cytoplasm nuclear pores
- (ER) extensive system of internal membranes that move proteins and other substances through the cell (made of lipid bilayer)
- endoplasmic reticulum
- a small, membrane-bound sac that transports substances in cells
- vesicle
- the rest of the ER is called ________ b/c it lacks ____________ and looks smooth
- smooth ER ribosomes
- set of flattened, membrane-bound sacs that serve as the packaging and distribution center of the cell
- Golgi apparattus
- small, sherical organelles that contain the cell's digestive enzymes
- lysosomes
- proteins are packaged into ________
- vesicles
- proteins are processed and then packaged into new vesicles
- Golgi apparatus
- Many of these vesicles move to the cell membrane and release their contents__________
- outside the cell
- digest and recycle the cell's used componets by breaking down proteins, nucleic acids, lipids, and carbs
- lysosomes
- organelle that harvests energy from organic compounds to make ATP
- mitochondrion
- mitochondria also have DNA and _________, and mitochondria make some of their own proteins
- ribosomes
- the cell membrane of a plant cell is surrounded by a thick cell wall, which supports and protects the cell
- cell wall
- organelles that use light energy to make carbohydrates from carbon dioxide and water
- chloroplasts
- chloroplasts are surrounded by two __________, contain their own DNA, and are thought to be the descendents of ____________ cells
- membranes prokaryotic
- found in both plants and animals, but only plants have a central vacuole
- central vacuole
- makes the cell _________ and able to stand up
- rigid